[dazzlevision]

Hello,

I have now replace all of the electrolytic capacitors on the three PCBs. For maximum reliability, I have used radial leaded plastic film types where the compactness of modern components allows (e.g. 2.2uF 50Vdc working). Several of the removed components were defective in one way or another.

I also replaced a 2.2uF 3V large green "CRL" branded disc ceramic, on the VHF/IF PCB, as it was quite leaky. There were two similar 470nF 3V “Erie” disc ceramics on the amplifier PCB, so I also replaced them (I’ve had these large value, low voltage disc ceramics give problems in Grundig transistor radios).

There were two blue sleeved Mullard axial electrolytics at the rear of the “function” selector switch, which I also replaced with plastic film types.

I then noticed that several of the “Erie” PCB “pluggable” type carbon composition resistors had cracks/splits in their end caps, which could result in noise/intermittency. Most of these had soldering “posts” on them, allowing external wires to be directly soldered to them (or indeed, select on test components – but not relevant in this case). I have used standard 0.25 or 0.5W leaded replacements, with a loop made at one end for any wiring to be connected.

The VHF preset station selection unit was rather intermittent and one button was broken off. In addition, the 24V 2.8W MES pilot lamp fitted just above it had rather discoloured the white plastic part. Luckily, I had a good, undamaged spare, which I partially dismantled, in order to clean the rather tarnished contacts on the five tuning sliders, the AFC defeat switch and the five “printed” carbon tracks. Access to the sliders is achieved by removing the five spring clips that hold the slider’s metal worm gear rods in place; the white plastic moulding then slides off.

Upon reassembling the VHF preset unit, I reconnected the wiring, connected temporary test loudspeakers to the amplifier PCB and switched on (in radio mode). I firstly checked the stabilised supply line was correct, which it was.

There was plenty of hiss from the speakers, so I connected an aerial and was rewarded with good quality mono radio, including Classic FM. The frequency range coverage marked on the control panel is only up to 100MHz, so I was lucky to be able to tune a little above this (the service manual spec says it tunes up to 101MHz).

The 24V MES pilot lamp was not lit, although the filament was intact on a cold Ohms test. So, I removed it and fitted a new spare. However, as it is likely to scorch the new VHF preset tuning unit, I will try to source an LED screw-in replacement for it.

There were a few modifications printed in a “BRC Bulletin” for this model, so I have incorporated them. This includes a 10nF mains rated capacitor across the mains transformer primary, in order to reduce “on-off switching noise” and adding a resistor onto the copper side of the 24V series regulator PCB (presumably to reduce output voltage drift).

I am lucky with this particular example, as there are AF126s fitted in the IF strip, although AF116s are shown in the BRC service manual. So, now tin whisker growth to deal with.

The next step will be to fit wires and a B7G plug onto my BRC SD1 stereo decoder unit and fit it in the space provided.

To be continued……………..